Bradenton, Fla. — Boston’s Jon Lackey retired the Pittsburgh Pirates on eight pitches in the first inning. Then he labored through a 35-pitch second inning.

“After the first inning being so quick, I definitely needed to throw a few pitches,” Lackey said after the Red Sox routed the Pittsburgh Pirates 16-6 yesterday. “It was more about getting up and down a couple times today. That was the biggest key for me.”

Lackey, who missed last season following elbow ligament-replacement surgery, was making his second spring training start. Pittsburgh took a 3-1 lead in the second when Brandon Inge and Clint Robinson singled, and Jared Goedert sent a curveball into the Red Sox bullpen beyond the left-field wall.

Lackey threw only fastballs in his one inning last weekend against Tampa Bay. He mixed in offspeed pitches against the Pirates.

“I threw a couple good ones, hung a couple,” he said. “A good step in the right direction. I’m still looking for a little bit of feel. But there hasn’t been any pain and I feel like my arm strength is getting better, so I’m encouraged.”

Lackey has been working on his cutter while throwing on flat ground and expects to throw a few in his next bullpen session. But his next outing, which likely will set slated for three innings, probably will be another fastball-breaking ball mix.

“These first few are definitely more about commanding the fastball than my secondary pitches,” Lackey said.

Pirates pitchers combined for 15 walks, including four with the bases loaded. Shortstop Josh Harrison made two throwing errors that allowed three runs to score.

Lyle Overbay drew a bases-loaded walk in a four-run third off left-hander Jonathan Sanchez, who gave up four runs, three hits and four walks in two-thirds of an inning.

Pittsburgh’s Zach Foster and Roman Colon combine to walk five in the fourth, including David Ross, Overbay and J.C. Linares with the bases full. Jose Iglesias capped the five-run inning with a two-run single.

Right-hander Jameson Taillon worked the first two innings for the Pirates. Among Pittsburgh’s top prospects, Taillon struck out three and allowed one run on one hit.

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Notes: Red Sox 3B Will Middlebrooks took batting practice, a few hours after being cleared by a wrist specialist. Middlebrooks left Wednesday night’s game when he felt pain in his right wrist on a checked swing. Middlebrooks broke the wrist last August when he was hit by a pitch.